public async Task <bool> OpenAsync()
{
var handle = new IntPtr();
NativeMethods.Open(deviceProfile, ref handle);
deviceHandle = new LibUsbDeviceHandle(handle);
NativeMethods.ClaimInterface(deviceHandle, 0);
isOpen = true;
pinListenerTask = new Task(async() =>
{
while (isOpen)
{
var buffer = new byte[41];
var len = 0;
try
{
var res = NativeMethods.BulkTransfer(deviceHandle, pinReportEndpoint, buffer, buffer.Length,
out len, 1000);
switch (res)
{
case LibUsbError.Success:
PinEventDataReceived?.Invoke(buffer);
break;
case LibUsbError.ErrorNoDevice:
case LibUsbError.ErrorPipe:
case LibUsbError.ErrorOverflow:
this.Close();
// HACK ALERT: device removal notifications don't seem to work right, so if we get ErrorNoDevice,
// request that ConnectionService remove the board that matches our device path.
((LibUsbConnectionService)ConnectionService.Instance).RemoveDevice(this.DevicePath);
break;
case LibUsbError.ErrorTimeout:
case LibUsbError.ErrorIO:
break; // normal behavior
default:
Debug.WriteLine("Pin Data Read Failure: " + res);
break;
}
}
catch (Exception ex)
{
Debug.WriteLine("Exception: " + ex.Message);
}
int rate = (int)Math.Round(1000.0 / UpdateRate);
if (rate > 1)
{
await Task.Delay(rate).ConfigureAwait(false);
}
}
});
pinListenerTask.Start();
return(true);
}
public static extern int ClaimInterface([In] LibUsbDeviceHandle deviceHandle, int interfaceNumber);
internal static extern LibUsbError BulkTransfer([In] LibUsbDeviceHandle deviceHandle, byte endpoint,
byte[] Data, int length, out int actualLength, int timeout);
public static extern int GetStringDescriptor([In] LibUsbDeviceHandle deviceProfileHandle, [In] byte desc_index,
StringBuilder sb, int length);
